How do you make ASW?

[drsyme]

Assuming you are starting with RO/DI water. Do you put in the salt and let it sit for 24 hours or so? Do you heat it? Do you put in an air bubbler? Please explain the rational with your answer, i.e. what difference does bubbling some air make? What is the effect of temp on S.G. and can you correct for this without using a heater? If you let it sit for a while, why?

Thanks for your help.

[tims]

hi , i can not answer all of them..but here is some of the info i have.....

ASW. making it up at least the day before. using a heater ( so you can get it to tank temp ( also goes into solution abit faster)). Having and air stone or power head so it keeps it mixing . this way you can check on the SG level after it has been mixing and you know it is solution.
i do not have the SG temp. difference chart but i imagine tom does.
but the SG level will measure differnt at various temps.
hope this helps you abit.. i will look around for the SG/temp chart.. i know i have seen one some where...

[tims]

here is some numbers i found..


Specific Gravity is temperature dependant.


Degrees F. Hydrometer reading.
50 1.0255
55 1.0252
60 1.0250
65 1.0246
70 1.0240
75 1.0233
80 1.0226
85 1.0218 (rather hot for most tanks)
90 1.0210 (very hot for most tanks)

[yardboy]

I mix mine up several days ahead as I make 55 gallons at the time and it takes a while to get it warm. I measure the salt 1 cup/ 2 gallons then adjust to 1.025 with a hydrometer. Once it's up to temp., I recheck and adjust so I don't have to do a temp. correction. I leave it recirculating (which I use to mix) using a Mag 7 pump.